Pruning of plum trees can also be divided into summer pruning and winter pruning. Summer pruning is carried out in the growing season, so it is also called growing season pruning; Winter pruning is carried out during the dormant period, so it is also called dormant pruning. Pruning in summer can generally be carried out for 3 ~ 5 times: 1 time after germination in spring, mainly to erase the buds with improper position and weak buds in the double buds, reduce invalid branches and save nutrition; The second time is the combination of thinning flowers and setting fruits, thinning branches and controlling competitive branches after flowering; After three times of hard core, the younger brother cut off the flourishing branches to promote the growth of secondary branches and increase the bearing area; The fourth time in early autumn and late autumn, the redundant secondary branches were cut short or thinned, and the long fruit branches were pitted, which slowed down the vegetative growth and promoted the flower bud differentiation. Careful pruning in summer can greatly reduce the workload of pruning in winter, and has obvious effects on saving tree nutrition, maintaining tree potential balance, increasing branch order and promoting flowering and fruiting.

Winter pruning is a supplementary pruning based on summer pruning, mainly to maintain tree-like and balanced growth, maintain the subordinate relationship between branches at all levels, and adjust the balance between vegetative growth and reproductive growth.

The common pruning methods of plum trees are: short cutting, thinning, shrinking and slow release.

(1) chopping is a part of pruning 1 annual branches, just like pruning other fruit trees. Due to the different severity of cutting, it can be divided into light cutting, medium cutting, heavy cutting and extremely heavy cutting. Light and short cutting refers to cutting about 1/4 of the vigorous1annual branches. Make the branches grow moderately, promote the growth of more short and middle branches, and be beneficial to the cultivation of various branches; 1 annual branch 1/3 ~ 1/2. Full buds are selected from the cutting mouth to promote the growth of medium and long branches, which are often used to cultivate tree skeletons and cut main branches and side branches; Heavy and short cutting refers to cutting off weaker 1 annual branches by more than 1/2, promoting the growth of branches, making the tree from weak to strong, and pruning by regeneration of main branches, lateral branches and fruiting branches; Extremely heavy short cutting is to leave only 2 ~ 3 weak buds at the base of branches for short cutting to promote the growth of medium and short branches, which is used to cultivate small and medium-sized fruit branches.

After the annual branches of Prunus mume/Kloc-0 were cut short, the growth intensity of branches was different because of the different quality of cutting buds, the position and extension direction of branches. The upright branches with full and vigorous cutting buds are easy to produce vigorous branches after short cutting, which can be used to cultivate the trunk of trees; On the contrary, it is easy to produce medium branches or weak branches, which can be used to cultivate fruiting branches. In general, short pruning is not conducive to the formation of flower buds, but for weak trees or branches, moderate short pruning can reduce the total number of branch buds, improve tree nutrition and be beneficial to flower bud differentiation. Proper pruning of long branches and middle branches can improve the fruit setting rate.

(2) Thinning: The branches are removed from the base for thinning. Proper thinning of branches that are too dense or improperly planted can improve ventilation and light transmission conditions, save nutrient consumption and be beneficial to flower bud differentiation. However, the number of sparse branches, especially the number of sparse perennial branches, should not be too much at a time, so as not to cause excessive growth and affect the yield of that year.

(3) Shrinking and shearing can make the perennial weak branches shrink, which is beneficial to the centralized supply of nutrients and promotes the regeneration and rejuvenation of weak trees.

(4) Slow-release part 1 annual branch, without any pruning, can slow down the growth of trees and is beneficial to flower bud differentiation. When the upright branch is slowly loosened, it must be smoothed or sprained from the base first, otherwise the effect is not good. Slow-release branches, after flowering and fruiting, must be cleaned in time, or cut short or retracted to prevent tree disorder.